Improved Method for Power Angle Rotor Subharmonic Measurement

It is a premise to acquire real time power angle for wide area measurement system(WAMS).In view of the problem of the common power angle measuring equipment which can't fix the zero-power angle when starting again after being stopped by some reason,the method for power angle measurement is improved by adding phasor graph of generator,which enables the equipment to work normally after disturbance,and combines the advantage of direct and indirect measurement method together.Theory analysis and simulation results show that the improved method is feasible.